The class of thermoplastic polymers is well known in the art, being particularly useful in part because of the property exhibited by many of the thermoplastic polymers of being deformable at relatively low temperatures. Thus, such polymers are processed by conventional techniques such as extrusion, injection molding or thermoforming into sheets, films, fibers, molded articles and other useful items without undue degradation of the polymer.
This property that makes many of the thermoplastics particularly useful, i.e., low temperature deformation, also precludes the use of such thermoplastics in engineering applications where exposure to elevated temperature is likely to be encountered. When relatively high temperature applications for thermoplastics are contemplated, it is often useful to employ a thermoplastic which incorporates, within the polymer chain, one or more types of cyclic moiety which typically raises the melting point or glass transition temperature of the polymer. One class of thermoplastics which on occasion incorporates a plurality of cyclic structures is the class of polyarylate polymers. The polyarylate polymers are frequently esters of aromatic diacids and dihydric phenol compounds. In such polymers, 2,2-di(4-hydroxyphenyl)propane, also known as bisphenol A or BPA, is often employed as the phenolic component. In copending U.S. patent application Ser. No. 314,515, filed Feb. 23, 1989, now U.S. Pat. No. 4,910,285 there is described a class of polyarylate polymers wherein moieties derived from a hydroxyarylsubstituted 1,6-diazaspiro[4.4]nonane-2,7-dione, and optionally a di(hydroxyphenyl)propane, alternate with a moiety of an aromatic dicarboxylic acid.
A second class of thermoplastic polymers is the class known as polycarbonates. These polycarbonates are also produced from aromatic bisphenols such as 2,2-di(4-hydroxyphenyl)propane, generally by reaction with phosgene or by ester exchange with a diaryl carbonate, e.g., diphenyl carbonate. In copending U.S. patent application Ser. No. 279,671, filed Dec. 5, 1988, now U.S. Pat. No. 4,906,725 there are disclosed polycarbonate polymers in which carbonyl groups alternate with moieties derived from a hydroxyarylsubstituted 1,6-diaza[4.4]spirodilactam, and optionally a moiety derived from a di(hydroxyphenyl)alkene. In the embodiment wherein moieties of two types of bisphenol are present, the relationship of the two types of moiety is random. A similar type of polymer of a regular, alternating structure of two bisphenol moieties is disclosed by copending U.S. patent application Ser. No. 411,775, filed Sept. 25, 1989.
Each of the polyarylate polymer and polycarbonate types exhibit properties that render them particularly useful for certain applications. It would be of advantage to provide polymers which incorporate bisphenol and other cyclic moieties which contain linking groups such as the ester or carbonyldioxy groups of the polycarbonate polymers and the carbonato or carbonyldioxy groups of the polycarbonate polymers.